Prenanthes racemosa
Prenanthes aspera
glaucous rattlesnakeroot, glaucous white lettuce, prenanthe à grappe, purple rattlesnake-root
rough rattlesnakeroot
erect, green or light purple, simple, (stout), glabrous and glaucous proximally, setose or hispid distally.
erect, green and mottled purple, glabrous proximally, midstems hispid or setose, scabrous to coarsely setose distally.
proximal usually present at flowering;
petioles broadly winged, (1–15 cm);
blades broadly oblanceolate to spatulate, 4–25 × 1–8 cm, coriaceous, bases attenuate, clasping, margins entire or weakly denticulate, apices obtuse or rounded, faces glabrous;
mid cauline sessile, clasping;
distal sessile and reduced.
proximalmost usually withered by flowering; petiolate (midcauline sessile, clasping);
blades spatulate, 4–11 × 2–5 cm, firm, coriaceous, brittle, bases attenuate, margins entire or weakly dentate, apices acute to obtuse, faces glabrate to roughly hispid abaxially;
distal reduced.
campanulate, 11–12 × 4–7 mm.
cylindric to campanulate, 12–17 mm.
9–29;
corollas usually pinkish, sometimes white or lavender, 7–13 mm.
8–19;
corollas pale yellow to creamy white, 9–17 mm.
7–14, green to purple, lanceolate to linear, 10–12 mm, margins scarious, sparsely to densely setose.
6–10, yellow green to tan, linear-lanceolate, 8–15 mm, coarsely setose.
of 8, dark green to purple, narrowly triangular-subulate bractlets 2–4 mm, coarsely setose.
of 6–12, green, triangular to lanceolate bractlets 2–5 mm, coarsely setose.
(ascending) in (elongate) narrowly racemiform or paniculiform arrays.
in erect, racemiform or narrowly paniculiform arrays.
golden brown, sub-cylindric, subterete, 5–6 mm, indistinctly 8–12-ribbed;
pappi pale yellow, 6–7 mm.
tan, subcylindric, subterete, 5–6 mm, irregularly 10–12-ribbed;
pappi pale yellow or brown, 7–8 mm.
= 16.
= 16.
Prenanthes racemosa
Prenanthes aspera
Prenanthes racemosa is recognized by its erect, stout, simple habit, glaucous stems, spatulate proximal leaves with broadly winged petioles and rounded to obtuse apices, heads borne in narrow racemiform arrays, purple and hairy phyllaries, and usually pinkish corollas. It is most similar to P. aspera, which differs in its generally smaller stature, more hirsute stems, leaves that are hispid abaxially, proximal leaves usually withered by flowering, and creamy white or yellow corollas. Hybrids between P. racemosa and P. trifoliolata, known as P. ×mainensis, occur in the northeastern United States and southeastern Canada (see discussion under P. trifoliolata).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Prenanthes aspera is easily recognized by its narrow, erect habit, unlobed, spatulate, weakly dentate leaves, basal leaves withered by flowering, heads in narrow, spiciform arrays, and densely setose phyllaries. The distribution closely matches that of the tall grass prairie, and like undisturbed prairies, this species is now rare or endangered in some states.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
BC
Flora NW
IL Wildflowers
MI Flora
MN Wildflowers
MO Plants
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
KS Wildflowers
LA Plants
